| dodge Ram 24valve Cummins front View
Too much heat will kill any transmission, no matter how good the internal parts may be. Whether you are cruising, crawling, dragging, playing in the dirt, or towing big toys, your transmission is creating friction and heat, and it's relying on the fluid for lubrication and cooling. Modern trucks include radiator-mounted transmission fluid to water-cooling tanks, and these are rarely adequate for the rigors of our favorite activities. Some towing packages include an auxiliary transmission oil cooler, but for those of you unwilling to leave your transmission at the mercy of factory parts, we'll show you how to install an aftermarket cooler. First, let's look at the three main types of transmission coolers available: fin and tube, stacked plate, and fin and plate.
Fin and TubeThe most traditional design uses a single tube to move fluid from one end of the cooler to the other. While in transit, the transmission oil passes by fins that transfer heat away from the fluid. This design works, but has the least amount of surface area in contact with the hot oil.
Stacked PlateThis is the most compact and durable type of fluid cooler. It is constructed out of multiple flat "tubes" (plates) with ridges to increase the surface area. Oil is cooled by air flowing through stacks of these plates. Since these coolers don't have fragile fins that can be bent, they are ideal for use on trucks that get hit with high-speed debris during bad weather and off-road adventures.
| The line that was routed from the transmission hard line to the factory cooler was re-routed to the "in" on the new cooler. We found the length was a perfect fit and required no trimming.
Fin and PlateUsing the best features of both coolers mentioned above, these units are durable and are the most efficient at removing heat from your transmission fluid. They combine the cooling power of stacked plates with extra space between the plates filled with fins to help disperse even more heat.
"For those of you unwilling to leave your transmission at the mercy of factory parts..."
The InstallOur guinea pig is a Dodge Ram with the 24-valve Cummins that's been upgraded with a larger turbo, bigger injectors, an Edge power module, upgraded intake, and an aftermarket exhaust system. In addition to all of the added power, this truck is mainly used for towing 18,000 pounds of toys. In other words, it's the perfect candidate for an auxiliary transmission cooler.
Our weapon of choice: a B&M Racing and Performance Products Hi-Tek fin and plate cooler sporting a 12-volt suction fan that's activated when fluid levels reach 175 degrees Fahrenheit. It took about half a day to install the cooler using some of the existing transmission oil lines and some that we had to fabricate. We also upgraded the transmission fluid to B&M Synthetic Trick Shift to help reduce wear and keep temperatures low.
During our freeway-towing test, we couldn't get the transmission to hit the 175-degree mark needed to engage the electric fan. While backing the trailer into our storage yard, we noticed a 40-degree temperature drop in the transmission while at stall. No wonder the cooling fan never kicked on! Adding this transmission cooler is truly a safety net. Here's how we did it
